In ΛCDM, the lengths of cosmic web filaments are expected to follow from the Gaussian initial density field and tidal shear, with numerical simulations predicting fairly specific correlations between filament length, the surrounding shear field, and smoothing scale (Bond et al. 1996; Pogosyan et al. 2009). Observational and simulation-based studies, however, find filaments that are longer, more coherent, or differently distributed with respect to the ambient tidal shear than simple ΛCDM plus halo-model expectations, suggesting either missing baryonic or dynamical effects or that the standard picture of how shear sculpts filament lengths is incomplete (Bond et al. 2010; Cautun et al. 2014).